Being a bicycle courier comes with its share of workplace hazards, including potholes, angry cab drivers and trucks with large blind spots. But one of the most insidious threats is the air the cyclists breathe, which, in congested urban corridors, can contain high levels of nitrogen dioxide (NO2), carbon monoxide (CO) and particulates emitted by diesel engines, which can cause health problems after long-term exposure and exacerbate any existing respiratory ailments, such as asthma.

Bike couriers in London, where NO2 levels along Oxford Street have been found to be among the highest in the world, are especially vulnerable to these environmental health risks. London, along with the English cities of Birmingham and Leeds, failed to meet safety limits on NO2, set by the European Union, for five years. And a 2015 study conducted by King's College London estimates that long-term exposure to air pollution leads to 9,500 premature deaths in that city each year.

Some of Gophr's couriers, holding CleanSpace tags

In order to quantify and monitor the air pollution to which these couriers are exposed, a U.K.-based delivery service called Gophr plans to outfit its London cycle couriers with sensors and location-tracking tags. The sensor tags are being provided by CleanSpace, a company that is building a crowdsourced map to measure air pollution in London. CleanSpace is owned by Drayson Technologies, a technology firm founded by Lord Paul Drayson, a British entrepreneur and politician. The sensor tags are powered by an RF-energy harvesting module made by Freevolt, which Drayson Technologies also owns.

"A good courier will [bike] 60 to 70 miles per day," says Gophr's founder, Seb Robert, so air pollution "is a massive issue for them." Plus, Robert says, outfitting cyclists with air-pollution sensors rather than putting the sensors on a conveyance that runs on fossil fuels, such as vehicles or motorcycles, helps Gophr's couriers to understand air pollution without also contributing to it.

The CleanSpace tag contains a Bluetooth radio that is used to pair the device to the courier's smartphone. The tag contains a carbon monoxide sensor and a thermistor. It does not measure NO2 or particulate suspended in the air, but, according to a news article in The Guardian, CO levels are used "as a surrogate for vehicle pollutants, such as fine particulates… and nitrogen dioxide." (IOT Journal reached out to CleanSpace and Drayson Technologies to confirm this and other information about the technology—such as how often or reliably the tag is able to harvest enough RF energy to collect, store and transmit the sensor data to the paired smartphone—but was told Lord Drayson is the sole spokesperson for CleanSpace, Drayson Technologies and Freevolt, and is currently unavailable.)